LCDs are used in a variety of electronic devices, including computers, smart phones, e-book readers, and televisions. Transmissive LCDs are typically used to achieve high brightness, contrast and color saturation. Such LCDs have an internal light source, known as a backlight, located at the back of the LCD. The LCD backlight usually comprises an array of LEDs, which can be white LEDs and/or tri-color RGB (red, green, blue) LEDs.
When forward biased, LEDs emit light, which is the sole purpose they serve in a conventional LCD backlight array. But, when exposed to light and reverse biased, LEDs are also capable of photovoltaic (PV) behavior, acting as photodiodes to generate electrical current. Given the increasing power demands of portable electronic devices with LCDs and the limitations of battery power sources, the present invention is designed to leverage the PV behavior of backlight LEDs as a secondary power source for portable LCDs.